Vacuum Technology Know How - Triumf

Material
Y 2O 3 / lr
W
Re
Relative intensity
www.pfeiffer-vacuum.net
100 %
5
CO 2 Vacuum
10
5
1
5
0.1
5
0.01
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 amu
Figure 4.7: Fractal ion distribution of CO 2
Table 4.1: Filament materials and their employment
Temperature
1,300 °C
1,800 °C
1,800 °C
Applicable Gases
Inert gases, Air / O2, NOx, SOx Inert gases, H2, halogens, freons
Inert gases,
hydrocarbons, H2, halogens, freons
Remarks
Mass number
Short service life with halogens, insensitive to
high O2 concentrations,
generates some CO / CO2 from O2 or H2O background
Short service life with O2 applications,
generates some CO / CO2 from O2 or H2O background,
C causes brittleness
Service life around three months due to
vaporization of the material,
used in connection with hydrocarbons
The various ion sources are described below on the basis of their attributes and fields of
application. What all ions have in common is that they can be electrically biased up to 150 V.
This avoids signal background due to ESD ions. This technology will be explained in
detail later.
Axial ion source
This ion source is characterized by its extremely robust mechanical design and high sensitivity.
It is primarily employed for residual gas analysis in high vacuum systems due to its open
construction. Figure 4.8 shows a schematic diagram of an axial ion source.
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